Behavior change campaigns are crucial in combatting illegal wildlife trade (IWT) by reducing demand, but assessing their impact requires robust strategies. The Behavior‐Centered Theory of Change (BC‐ToC) integrates Theory of Change frameworks with decision‐making models to design and evaluate interventions using behavioral and progress indicators. We used BC‐ToC to design two behavioral change interventions aimed at reducing demand for two threatened Venezuelan bird species: the Yellow‐shouldered Amazon (YSA) and the Red Siskin (RS). We developed workshops to engage community organizations and conservationists to identify audience groups, evaluate alternative behaviors considering impact and benefits, and define behavior‐based indicators for monitoring change. For YSA, two audience groups with similar demand motivations emerged: “common folks” (women, 20–70 yo, low education) and “young professionals” (20–30 yo, educated). Enjoying parrots through outdoor activities emerged as an alternative. For RS, the main audience segments were the breeder groups “South American node” (Venezuelan and Brazilian) and “Iberian node” (Spaniels and Portuguese). Iberian with wider age range (30–60 yo) and greater education than South American. Adopting responsible sourcing practices surfaced as the alternative behavior. We described behavioral levers, intermediary outputs, and indicators reflecting changes in knowledge, attitudes, norms, and control. We discussed challenges for adoption, emphasizing systemic barriers and the role of regulations, and provided ground‐tailored strategies for effective behavioral interventions.